Google is pushing active military personnel to the front of the Google Voice waiting list. That means if you have a .mil email address, an invite will go out inside 24 hours of your request.
The move is intended to assist servicemen and women abroad that would otherwise have difficulty directly contacting loved ones. Army SGT Dale Sweetnam explains on Google's Official Blog:
When you deploy, your life is put on hold. While you live and work in a different world, everyone else moves on with life back home. Your family and friends keep moving, and this sometimes means it's just not possible for them to stay awake until 2 a.m. to receive a phone call. Calling Iraq or Afghanistan is seldom an option.
Google Voice provides a solution to some of these problems. Service members can set up an account before they deploy. Or if they're already deployed, families can now set up an account for their service member. Loved ones can call to leave messages throughout the day, and then when that service member visits an Internet trailer, all the messages are right there. It's like a care package in audio form.